This invention relates to a new and useful device for testing and/or temporarily correcting circuits in a vehicle electrical system.
It is customary in the larger type road vehicles such as truck and trailer assemblies, recreational vehicles, and the like, to utilize a junction on the pulling vehicle arranged for plug-in connection with a cord containing wires leading to the lights on the trailing vehicle, each of the circuits in the trailing vehicle being associated with a power circuit from the pulling vehicle extending through the junction.
When the vehicle is on the road, it is extremely inconvenient and sometimes dangerous to the driver, as well as to other vehicles on the highway, when short circuits develop in the circuits. In such a case, circuit breakers will generally open, causing an entire circuit of lights to become ineffective and making it impossible or difficult for the vehicle to proceed. If the driver re-sets the circuit breakers while a short circuit still exists, there may be danger of overheating of circuit wires and a resulting fire. To find the source of trouble, the driver must operate the various actuating switches which control the light circuits and walk around to determine the defective circuit. If he is alone, it is generally impossible to find a short circuit since if the circuit breaker is closed it will again open before the driver can get around to the side or back of the vehicle.
The above problems and others have been recognized in the trade and devices for testing circuits have heretofore been devised in an attempt to overcome them. One such device is shown in U.S. Pat. No. 3,836,843 and employs a plug-in body member having a plurality of lamps which indicate a defective power circuit from the pulling vehicle when a suitable ground is established between a metal handle on the device and the body of the vehicle. This testing device has several disadvantages one of which is that the operator must establish a ground on the vehicle and another of which is that the device is merely a tester and does not provide any help for the driver to correct the problem at least to the extent which will allow him to proceed to a repair station.